Lizard navigate with third eye
Lizards has a third eye. The third eye, or parietal eye, is mostly a patch of light-sensetive cells located between the regular eyes which the lizards use for navigation, biologists from the University of Ferrera in Italy has found.
[The Italian biologists] trained Italian wall lizards to swim from the center of a small outdoor swimming pool to a hidden ledge at its edge. A fence was erected around the pool, so that the only visual point of reference was the position of the sun. The lizards passed the test.
However, after the lizards had been kept indoors where the lights brightened and dimmed out-of-sync with the sun’s natural cycle, they swam in different direction.
How off the mark they was depended on how much their body clock had been screwed with by the artificial lighting. And if the third eye was covered – or removed – the lizards could not navigate at all.